Buffer air flow reversal has been known to occur in some engine transcient conditions and can be related to bearing seal wear. During flow reversal, bearing oil which is normally retained into the bearing cavity by the greater buffer air pressure at the entry point, becomes instead entrained away from the bearing cavity by the bearing cavity pressure being higher than the buffer air pressure at the entry point. If a path is present between the entry point and the gas path, upstream of a bleed air feed for cabin pressurization, oil contaminated air can potentially make its way into the cabin which is undesired. Accordingly, there remains room for improvement in addressing bearing buffer air flow reversal in gas turbine engines.